This invention relates to compositions that include at least one fluoroether and at least one hydrofluorocarbon. Such compositions may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, displacement drying agents and as carriers for sterilant gases.
Included in this invention are compositions which include a fluoroether and a hydrofluorocarbon in which the halocarbon global warming potential (HGWP) of the hydrofluorocarbon is lowered by adding the fluoroether to the hydrofluorocarbon. Also included in this invention are compositions a fluoroether and a hydrofluorocarbon that are azeotropic or azeotrope-like.
Fluorinated hydrocarbons have many uses, one of which is as a refrigerant. Such refrigerants include dichlorodifluoromethane (CFC-12) and chlorodifluoromethane (HCFC-22).
In recent years it has been suggested that certain chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants released into the atmosphere may adversely affect the ozone layer. Although this proposition has not yet been completely established, there is a movement toward the control of the use and the production of certain CFCs and HCFCs under an international agreement.
In order to address the potential problem of ozone depletion, it has been suggested that chlorofluorocarbon refrigerants and hydrochlorofluorocarbon refrigerants be replaced with hydrofluorocarbon refrigerants. Since the hydrofluorocarbon (HFC) refrigerants contain no chlorine, they have zero ozone depletion potential.
Another environmental concern is the role of CFCs in the xe2x80x9cgreenhouse effectxe2x80x9d. The greenhouse effect refers to the warming of the Earth""s climate that takes place when atmospheric gases, which are relatively transparent to visible light and allow sunshine to reach the Earth, trap heat by absorbing infrared radiation released by the Earth.
There is presently no universally accepted methodology for combining all relevant factors into a singe global warming potential for emissions of gases such as CFCs. One approach is to define the greenhouse effect of a compound in terms of a potential to enhance global warming relative to a known standard. One such definition is known as a halocarbon global warming potential (HGWP), which is the ratio of incremental radiative warming resulting from an emission of a gas, over the lifetime of the gas in the atmosphere, to the calculated warming that would result from a release of the same mass of reference gas CFC-11.
While HFCs may have a zero ozone depletion potential, some HFCs may have an HGWP that may be undesirable and subject to governmental regulation. Accordingly, there is also a demand for the development of refrigerants that have a low ozone depletion potential while at the same time having a low HGWP.
It is preferred that refrigerants that include more than one component be azeotropic or azeotrope-like so that the composition of the refrigerant does not change when leaked or discharged to the atmosphere from refrigeration equipment. A change in composition of a refrigerant may affect its properties, such as performance or flammability.
It is also desirable to use compositions that have a low ozone depletion potential and/or a low HGWP and/or that are azeotropic or azeotrope-like as cleaning agents, blowing agents in the manufacture of closed-cell polyurethane, phenolic and thermoplastic foams, as propellants in aerosols, as heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, such as for heat pumps, inert media for polymerization reactions, fluids for removing particulates from metal surfaces, as carrier fluids that may be used, for example, to place a fine film of lubricant on metal parts, or as buffing abrasive agents to remove buffing abrasive compounds from surfaces such as metal, as displacement drying agents for removing water, such as from jewelry or metal parts, as resist developers in conventional circuit manufacturing techniques including chlorine-type developing agents, and as strippers for photoresists when used with, for example, a chlorohydrocarbon, such as 1,1,1-trichloroethane or trichloroethylene.
This invention relates to compositions that include a fluoroether and a hydrofluorocarbon. Included in this invention are compositions of a cyclic or acyclic hydrofluoroether of the formula CaFbH2a+2xe2x88x92bOc wherein a=2 or 3 and 3xe2x89xa6bxe2x89xa68 and c=1 or 2 and a hydrofluorocarbon of the formula CnFmH2n+2xe2x88x92m wherein 1xe2x89xa6nxe2x89xa64 and 1xe2x89xa6mxe2x89xa68. Such compositions may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.
Another aspect of this invention relates to the discovery that the HGWP of a hydrofluorocarbon can be lowered by adding to the hydrofluorocarbon a fluoroether having a lower HGWP than the HGWP of the hydrofluorocarbon. Accordingly, the present invention relates to a composition of a first component that includes a hydrofluorocarbon and a second component that includes a fluoroether that has an HGWP less than the HGWP of the first component, such that the HGWP of the composition is less than the HGWP of the first component.
Also included in this invention are compositions which include a fluoroether and a hydrofluorocarbon that are azeotropic or azeotrope-like.
The present invention relates to compositions that include a fluoroether and a hydrofluorocarbon (HFC). Included in this invention are compositions of a cyclic or acyclic hydrofluoroether of the formula CaFbH2a+2xe2x88x92bOc wherein a=2 or 3 and 3xe2x89xa6bxe2x89xa68 and c=1 or 2 and a hydrofluorocarbon of the formula CnFmH2n+2xe2x88x92mwherein 1xe2x89xa6nxe2x89xa64 and 1xe2x89xa6mxe2x89xa68. These compositions may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.
The fluoroethers that are included in this invention have two or three carbon atoms. Examples of such fluoroethers include the following.
1. Hexafluorodimethyl ether (116E, or CF3OCF3, boiling point=xe2x88x9259.0xc2x0 C.),
2. Pentafluorodimethyl ether (125E, or CHF2OCF3, boiling point=xe2x88x9236.2xc2x0 C.),
3. Bis(difluoromethyl) ether (134E, or CHF2OCHF2, boiling point=5xc2x0 C.),
4. Fluoromethyl trifluoromethyl ether (134aE, or CH2FOCF3, boiling point=xe2x88x9220.0xc2x0 C.),
5. Trifluoromethyl methyl ether (143aE, or CH3OCF3, boiling point=xe2x88x9224.2xc2x0 C.),
6. Perfluorooxetane (C-216E 
xe2x80x83boiling point=xe2x88x9229.2xc2x0 C.),
7. 2,2,4,4,5,5-hexafluoro-1,3-dioxolane (C-216E2 or C3F6O2, having a structure of 
xe2x80x83boiling point=xe2x88x9222.1xc2x0 C.),
8. Perfluoromethyl ethyl ether (218E, or CF3OCF2CF3, boiling point=xe2x88x9223.3xc2x0 C.),
9. Perfluorodimethoxymethane (218E2, or CF3OCF2OCF3, boiling point=xe2x88x9210.2xc2x0 C.),
10. 2,2,3,4,4-pentafluorooxetane (C-225eExcex1xcex2, or C3HF5O, having a structure of 
xe2x80x83boiling point=3.4xc2x0 C.),
11. 1-trifluoromethoxy-1,1,2,2-tetrafluoroethane (227caExcex1xcex2, or CF3OCF2CHF2, boiling point=about xe2x88x923xc2x0 C.),
12. Difluoromethoxy pentafluoroethane (227caExcex2xcex3, or CHF2OCF2CF3, boiling point=xe2x88x928.0xc2x0 C.),
13. 1-trifluoromethoxy-1,2,2,2-tetrafluoroethane (227eaE, or CF3OCHFCF3, boiling point=xe2x88x929.4xc2x0 C.),
14. 2,2,4,4-tetrafluorooxetane (C-234fExcex1xcex2, or C3H2F4O, having a structure of 
xe2x80x83boiling point=21.2xc2x0 C.),
15. 2,2,3,3-tetrafluorooxetane (C-234fExcex2xcex3, or C3H2F4O, having a structure of 
xe2x80x83boiling point=28xc2x0 C.),
16. 1-difluoromethoxy-1,1,2,2-tetrafluoroethane (236caE, or CHF2OCF2CHF2, boiling point=28.5xc2x0 C.),
17. 1-dffluoromethoxy-1,2,2,2-tetrafluoroethane (236eaExcex2xcex3, or CHF2OCHFCF3, boiling point=23.2xc2x0 C.),
18. 1-trifluoromethoxy-2,2,2-trifluoroethane (236faE, or CF3OCH2CF3, boiling point=5.6xc2x0 C.),
19. 1-difluoromethoxy-2,2,2-trifluoroethane (245faExcex2xcex3, or CHF2OCH2CF3, boiling point=29xc2x0 C.).
116E (CAS Reg. No. 1479-49-8) has been prepared by electrochemical fluorination of dimethyl ether as disclosed by Simons in U.S. Pat. No. 2,519,983.
125E (CAS Reg. No. 3822-68-2) has been prepared by electrochemical fluorination of dimethyl ether (CH3OCH3) as disclosed by Fox, et. al. in U.S. Pat. No. 3,511,760 and by Hutchinson in U.S. Pat. No. 3,887,439.
134E (CAS Reg. No. 1691-17-4) can be prepared by reaction of antimony trifluoride with CHF2OCHCl2 as disclosed by O""Neill in GB 2,248,617.
134aE (CAS Reg. No. 2261-01-0) has been made by the electrochemical fluorination of methyl 2-methoxypropionate as reported by Berenblit, et. al. Zh. Org. Khim., Vol. 12, pp. 767-770 (1976).
143aE (CAS Reg. No. 421-14-7) has been made by the reaction of methyl fluoroformate with sulfur tetrafluoride as reported by Aldrich and Sheppard, J. Am. Chem. Soc., Vol. 29, 11-15 (1964).
C-216E (CAS Reg. No. 425-82-1) can be made by electrochemical fluorination of trimethylene oxide (oxetane) in anhydrous hydrogen fluoride as disclosed by Kauck and Simons in U.S. Pat. No. 2,594,272.
C-216E2 (CAS Reg. No. 21297-65-4) has been prepared by UV irradiation of perfluoro-b-oxa-d-valerolactone in the vapor or liquid phase as reported by Throckmorton in J. Org. Chem., Vol. 34, pp. 3438-3440 (1969). The lactone was prepared by the reaction of KF with perfluorooxydiacetyl chloride.
218E (CAS Reg. No. 665-16-7) has been made by direct fluorination of CF3OCH2CF3 (prepared by reaction of CF3OF with vinylidene fluoride) as reported by Sekiya and Ueda in Chemistry Letters, pp. 609-612 (1990).
218E2 (CAS Reg. No. 53772-78-4) was made in the electrochemical fluorination of methyl 2-methoxypropionate as reported by Berenblit, et. al. Zh. Org. Khim., Vol. 12, pp. 767-770 (1976).
C-225eExcex1xcex2 (CAS Reg. No. 144109-03-5) may be prepared by direct fluorination of trimethylene oxide (cyclo-CH2CH2CH2Oxe2x80x94) using techniques described by Lagow and Margrave in Progress in Inorganic Chemistry, Vol. 26, pp. 161-210 (1979) or by Adcock and Cherry in Ind. Eng. Chem. Res., Vol. 26, pp. 208-215 (1987). The direct fluorination is carried out to the desired level of fluorine incorporation into the starting material, and products receovered by fractional distillation.
227caExcex1xcex2 (CAS Reg. No. 2356-61-8) has been prepared by reacting difluoroacetyl fluoride with cesium fluoride and carbonyl fluoride followed by treatment with sulfur tetrafluoride as disclosed by Eisemann in U.S. Pat. No. 3,362,190.
227caExcex2xcex3 (CAS Reg. No. 53997-64-1) has been made by electrochemical fluorination of CHCl2OCF2CHClF as reported by Okazaki, et. al. J. Fluorine Chem., Vol. 4, pp. 387-397 (1974).
227eaE (CAS Reg. No. 2356-62-9) was prepared by reacting 2-trifluoromethoxy-tetrafluoropropionyl fluoride (CF3CF(OCF3)COF) with aqueous potassium hydroxide at 230xc2x0 C. as disclosed by Eisemann in U.S. Pat. No. 3,362,190.
C-234fExcex1xcex2 may be prepared by direct fluorination of trimethylene oxide (cyclo-CH2CH2CH2Oxe2x80x94) using techniques described by Lagow and Margrave in Progress in Inorganic Chemistry, Vol. 26, pp. 161-210 (1979) or by Adcock and Cherry in Ind. Eng. Chem. Res., Vol. 26, pp. 208-215 (1987). The direct fluorination is carried out to the desired level of fluorine incorporation into the starting material, and products receovered by fractional distillation.
C-234fExcex2xcex3 (CAS Reg. No. 765-63-9) has been prepared by Weinmayr (J. Org. Chem., Vol. 28, pp. 492-494 (1963)) as a by-product from the reaction of TFE with formaldehyde in HF.
236caE (CAS Reg. No. 32778-11-3) has been prepared by fluorination of CHCl2OCF2CHF2 (prepared in turn by chlorination of CH3OCF2CHF2) using anhydrous hydrogen fluoride with antimony pentachloride catalyst as reported by Terrell, et. al. in J. Medicinal Chem., Vol. 15, pp. 604-606 (1972).
236eaExcex2xcex3 (CAS Reg. No. 57041-67-5) has been prepared by chlorination of methoxy acetyl chloride to give the intermediate, CHCl2OCHClCOCl, which was isolated and reacted with sulfur tetrafluoride at 150C to give the product as disclosed by Halpern and Robin in U.S. Pat. No. 4,888,139.
236faE (CAS Reg. No. 20193-67-3) has been prepared by reaction of 2,2,2-trifluoroethanol with carbonyl fluoride to give the intermediate, CF3CH2OCOF, which was in turn reacted with sulfur tetrafluoride at 150-200xc2x0 C. to give the product as disclosed by Eisemann in U.S. Pat. No. 3,394,878.
245faExcex2xcex3 (CAS Reg. No. 1885-48-9) has been prepared by the reaction of chlorodifluoromethane with trifluoroethanol in the presence of potassium hydroxide as disclosed by Croix in U.S. Pat. No. 3,637,477.
The HFCs that may be combined with the fluoroethers include one or more of the following: difluoromethane (HFC-32), fluoromethane (HFC-41), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134),1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2-trifluoroethane (HFC-143), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,3,3,3-hexafluoro-propane (HFC-236fa), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 1,1,1,2,2,3-hexafluoropropane (HFC-236cb), 1,1,2,2,3-pentafluoropropane (HFC-245ca), 1,1,1,2,2-pentafluoropropane (HFC-245cb), 1,1,2,3,3-pentafluoropropane (HFC-245ea), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,2,2,3-tetrafluoropropane (HFC-254ca), 1,1,2,2-tetrafluoropropane (HFC-254cb), 1,1,1,2-tetrafluoropropane (HFC-254eb), 1,2,2-trifluoropropane (HFC-263ca), 1,1,1-trifluoropropane (HFC-263fb), 2,2-difluoropropane (HFC-272ca), 1,2-difluoropropane (HFC-272ea), 1,1-difluoropropane (HFC-272fb), 2-fluoropropane (HFC-281ea), 1-fluoropropane (HFC-281fa), 1,1,1,3,3,4,4,4-octafluorobutane (HFC-338mf), 1,1,1,4,4,4-hexafluorobutane (HFC-356mff), or (CF3)2CHCH3, (HFC-356 mmz).
The following can be used as refrigerants: compositions of a cyclic or acyclic hydrofluoroether of the formula CaFbH2a+2xe2x88x92bOc wherein a=2 or 3 and 3xe2x89xa6bxe2x89xa68 and c=1 or 2 and a hydrofluorocarbon of the formula CnFmH2n+2xe2x88x92mwherein 1xe2x89xa6nxe2x89xa64 and 1xe2x89xa6mxe2x89xa68. Examples of such compositions include the following.
1-99 weight percent 116E and 1-99 weight percent HFC-32, HFC-41, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236ea, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 125E and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 134E and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236ea, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, HFC-281fa, HFC-338mf or 356mff.
1-99 weight percent 134aE and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 143aE and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent C216E, and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent C-216E2 and 1-99 weight percent HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, or HFC-245cb.
1-99 weight percent 218E and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 218E2 and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fa, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent C-225eExcex1xcex2 and 1-99 weight percent HFC-143, HFC-236cb, HFC-236ea, or HFC-245cb.
1-99 weight percent 227caExcex2xcex3 and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 227caExcex2xcex3 and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 227eaE and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent C-234fExcex1xcex2 and 1-99 weight percent HFC-245cb, HFC-245eb, HFC-356mff or HFC-356mmz.
1-99 weight percent C-234fExcex2xcex3 and 1-99 weight percent HFC-245ca, HFC-245cb, HFC-245ea, HFC-254ca, HFC-356mff or HFC-356 mmz. 1-99 weight percent 236caE and 1-99 weight percent HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 236eaExcex2xcex3 and 1-99 weight percent HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, HFC-281fa, HFC-338mf, HFC-356mff or HFC-356 mmz.
1-99 weight percent 236faE and 1-99 weight percent HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, or HFC-281fa.
1-99 weight percent 245faExcex2xcex3 and 1-99 weight percent HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a, HFC-161, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236fa, HFC-245ca, HFC-245cb, HFC-245ea, HFC-245fa, HFC-254ca, HFC-254cb, HFC-254eb, HFC-263ca, HFC-263fb, HFC-272ca, HFC-272ea, HFC-272fb, HFC-281ea, HFC-281fa, or HFC-356mff. The present invention also relates to the discovery of azeotropic or azeotrope-like compositions of effective amounts of the following compounds to form an azeotropic or azeotrope-like composition at a specific temperature or pressure:
116E and HFC-32, HFC-41, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a or HFC-161; 125E and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a or HFC-161; 134E and HFC-143, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236ea, HFC-236fa, HFC-245cb, HFC-254cb, HFC-254eb, HFC-338mf, or HFC-356mff; 134aE and HFC-32, HFC-134, HFC-143, HFC-152a, HFC-227ca, HFC-227ea or HFC-245cb; 143aE and HFC-32, HFC-134, HFC-143a, HFC-152a, HFC-227ca, HFC-227ea or HFC-245cb; C216E and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-245cb; C216E2 and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-245cb; 218E and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-263fb; 218E2 and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-236fa or HFC-263fb; C-225eExcex1xcex2 and HFC-143, HFC-236cb, HFC-236ea or HFC-245cb; 227caExcex1xcex2 and HFC-32, HFC-143, HFC-245cb, HFC-272ca, HFC-281ea or HFC-281fa; 227caExcex2xcex3 and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-263fb, HFC-272ca, HFC-281ea or HFC-281fa; 227eaE and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-263fb, HFC-272ca, HFC-281ea or HFC-281fa; C-234fExcex1xcex2 and HFC-245cb, HFC-245eb, HFC-356mff or HFC-356mmz; C-234fExcex2xcex3 and HFC-245ca, HFC-245cb, HFC-245ea, HFC-254ca, HFC-356mff or HFC-356 mmz; 236caE and HFC-143, HFC-245ca, or HFC-254ca; 236eaExcex2xcex3 and HFC-143, HFC-245ca, HFC-263ca, HFC-338mf, HFC-356mff or HFC-356 mmz; or 236faE and HFC-32, HFC-143, HFC-272ca, HFC-272fb or HFC-281fa; 245faExcex2xcex3 and HFC-356mff.
By xe2x80x9cazeotropicxe2x80x9d composition is meant a constant boiling liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without compositional change. Constant boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, as compared with that of the non-azeotropic mixtures of the same components.
By xe2x80x9cazeotrope-likexe2x80x9d composition is meant a constant boiling, or substantially constant boiling, liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotrope-like composition is that the vapor produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without substantial compositional change.
It is recognized in the art that a composition is azeotrope-like if, after 50 weight percent of the composition is removed such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is less than 10 percent, when measured in absolute units. By absolute units, it is meant measurements of pressure and, for example, psia, atmospheres, bars, torr, dynes per square centimeter, millimeters of mercury, inches of water and other equivalent terms well known in the art. If an azeotrope is present, there is no difference in vapor pressure between the original composition and composition remaining after 50 weight percent of the original composition has been removed.
Therefore, included in this invention are compositions of effective amounts of a fluoroether and an HFC such that after 50 weight percent of an original composition is evaporated or boiled off to produce a remaining composition, the difference in the vapor pressure between the original composition and the remaining composition is about 10 percent or less. Examples of such compositions include the following:
116E and HFC-32, HFC-41, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152a or HFC-161; 125E and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a or HFC-161; 134E and HFC-143, HFC-227ca, HFC-227ea, HFC-236ca, HFC-236cb, HFC-236ea, HFC-236fa, HFC-245cb, HFC-254cb, HFC-254eb, HFC-338mf or HFC-356mff; 134aE and HFC-32, HFC-134, HFC-143, HFC-152a, HFC-227ca, HFC-227ea or HFC-245cb; 143aE and HFC-32, HFC-134, HFC-143a, HFC-152a, HFC-227ca, HFC-227ea or HFC-245cb; C216E and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-245cb; C-216E2 and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-245cb; 218E and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161 or HFC-263fb; 218E2 and HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-236fa or HFC-263fb; C-225eExcex1xcex2 and HFC-143, HFC-236cb, HFC-236ea or HFC-245cb; 227caExcex1xcex2 and HFC-32, HFC-143, HFC-245cb, HFC-272ca, HFC-281ea or HFC-281fa; 227caExcex2xcex3 and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-263fb, HFC-272ca, HFC-281ea or HFC-281fa; 227eaE and HFC-32, HFC-134, HFC-134a, HFC-143, HFC-152a, HFC-161, HFC-263fb, HFC-272ca, HFC-281ea or HFC-281fa; C-234fExcex1xcex2 and HFC-245cb, HFC-245eb, HFC-356mff or HFC-356mmz; C-234fExcex2xcex3 and HFC-245ca, HFC-245cb, HFC-245ea, HFC-254ca, HFC-356mff or HFC-356 mmz; 236caE and HFC-143, HFC-245ca or HFC-254ca; 236eaExcex2xcex3 and HFC-143, HFC-245ca, HFC-263ca, HFC-338mf, HFC-356mff or HFC-356 mmz; 236faE and HFC-32, HFC-143, HFC-272ca, HFC-272fb or HFC-281fa; or 245faExcex2xcex3 and HFC-356mff.
Substantially constant boiling, azeotropic or azeotrope-like compositions of this invention comprise the following (all at 25xc2x0 C.):
For purposes of this invention, xe2x80x9ceffective amountxe2x80x9d is defined as the amount of each component of the inventive compositions which, when combined, results in the formation of an azeotropic or azeotrope-like composition. This definition includes the amounts of each component, which amounts may vary depending on the pressure applied to the composition so long as the azeotropic or azeotrope-like compositions continue to exist at the different pressures, but with possible different boiling points.
Therefore, effective amount includes the amounts, such as may be expressed in weight percentages, of each component of the compositions of the instant invention which form azeotropic or azeotrope-like compositions at temperatures or pressures other than as described herein.
For the purposes of this discussion, azeotropic or constant-boiling is intended to mean also essentially azeotropic or essentially-constant boiling. In other words, included within the meaning of these terms are not only the true azeotropes described above, but also other compositions containing the same components in different proportions, which are true azeotropes at other temperatures and pressures, as well as those equivalent compositions which are part of the same azeotropic system and are azeotrope-like in their properties. As is well recognized in this art, there is a range of compositions which contain the same components as the azeotrope, which will not only exhibit essentially equivalent properties for refrigeration and other applications, but which will also exhibit essentially equivalent properties to the true azeotropic composition in terms of constant boiling characteristics or tendency not to segregate or fractionate on boiling.
It is possible to characterize, in effect, a constant boiling admixture which may appear under many guises, depending upon the conditions chosen, by any of several criteria:
The composition can be defined as an azeotrope of A, B, C (and D . . . ) since the very term xe2x80x9cazeotropexe2x80x9d is at once both definitive and limitative, and requires that effective amounts of A, B, C (and D . . . ) for this unique composition of matter which is a constant boiling composition.
It is well known by those skilled in the art, that, at different pressures, the composition of a given azeotrope will vary at least to some degree, and changes in pressure will also change, at least to some degree, the boiling point temperature. Thus, an azeotrope of A, B, C (and D . . . ) represents a unique type of relationship but with a variable composition which depends on temperature and/or pressure. Therefore, compositional ranges, rather than fixed compositions, are often used to define azeotropes.
The composition can be defined as a particular weight percent relationship or mole percent relationship of A, B, C (and D . . . ), while recognizing that such specific values point out only one particular relationship and that in actuality, a series of such relationships, represented by A, B, C (and D . . . ) actually exist for a given azeotrope, varied by the influence of pressure.
An azeotrope of A, B, C (and D . . . ) can be characterized by defining the compositions as an azeotrope characterized by a boiling point at a given pressure, thus giving identifying characteristics without unduly limiting the scope of the invention by a specific numerical composition, which is limited by and is only as accurate as the analytical equipment available.
The azeotrope or azeotrope-like compositions of the present invention can be prepared by any convenient method including mixing or combining the desired amounts. A preferred method is to weigh the desired component amounts and thereafter combine them in an appropriate container.
There is no universally accepted methodology for combining all relevant factors into a single global warming potential for greenhouse gas emissions. One way to define the greenhouse effect of a compound is to determine its potential to enhance global warming relative to a known standard. In the present invention, the halocarbon global warming potential (HGWP) of several fluoroethers and HFCs were determined using known estimating techniques.
HGWP is defined as the ratio of incremental radiative warming resulting from an emission of a gas, over the lifetime of the gas in the atmosphere, to the calculated warming that would result from a release of the same mass of reference gas CFC-11, which has an HGWP of 1.0. The calculation of HGWP is discussed in Fisher et. al., Model Calculations on the Relative Effects of CFCs and their Replacements on Global Warming. Nature, Volume 344, pp. 513-516 (1990), the text of which is incorporated herein by reference.
It has been discovered that the HGWP of an HFC can be lowered by adding to the HFC a fluoroether having a lower HGWP than the HGWP of the HFC such that the combination of the HFC and the fluoroether has an HGWP lower than the HGWP of the HFC. Therefore, the present invention relates to a composition of a first component that includes a hydrofluorocarbon and a second component that includes a fluoroether that has an HGWP less than the HGWP of the first component, such that the HGWP of the composition is less than the HGWP of the first component.
The scope of this invention includes a single fluoroether compound added to a single HFC, as well as a single fluoroether added to mixtures of two or more HFCs. Further, the invention includes mixtures of one or more fluoroethers added to a single HFC, as well as mixtures of one or more fluoroethers added to mixtures of two or more HFCs.
The HGWP of a composition of components A and B is equal to
[fractional composition of A]xc3x97[HGWP of A]+[fractional composition of B]xc3x97[HGWP of B]. The HGWP of a composition of more than two components is determined in the same way, that is, by multiplying the fractional composition of a component by its HGWP, and then adding together the fractional HGWPs of all the components.
Specific examples illustrating the invention are given below. Unless otherwise stated therein, all percentages are by weight. It is to be understood that these examples are merely illustrative and in no way are to be interpreted as limiting the scope of the invention. All values given in the Examples are +/xe2x88x925 percent.